The invention relates to a process for increasing the molecular weight and/or viscosity of polycondensates which remain thermoformable after the process.
Polycondensates, such as polyamides, polyesters and polycarbonates, are important engineering plastics with a wide variety of potential uses, for example in the form of films, bottles, fibers and injection mouldings. It is common to these polymers that they are prepared by polycondensation reactions.
Damage to such polycondensates through processing and use leads, owing to chain cleavage, to polymer fragments containing functional end groups.
The mechanical and physical properties of polymers are crucially dependent on the molecular weight of the polymer. High-grade recycling of used polyesters, polyamides and polycarbonates from production wastes, for example from fiber production and injection moulding, is only possible to a restricted extent without aftertreatment, owing to the reduced molecular weight. For certain applications there is also a demand for high molecular mass virgin polycondensates, the synthesis of which is difficult.
Increasing the molecular weight of polycondensates such as polyamides or polyesters, for example, is known in principle. One possibility, for example, is post-condensation in the solid state (xe2x80x9csolid state polycondensationxe2x80x9d) as is described in xe2x80x9cUllmann""s Encyclopedia of Industrial Chemistry Vol. A 21, 5th Editionxe2x80x9d, page 188 [polyamides] and page 236 [polyesters] (1992) and is also practised industrially. An alternative method is the build-up of molecular weight by means of reactive additives, such as epoxides, tetracarboxylic dianhydrides, diisocyanates, bisoxazolines or dicarboxylic bisimides, which is referred to in general as chain extension and is disclosed, for example, in EP-A-0 074 337.
EP-A-0 604 367 discloses a process for increasing the molecular weight of polyamides which comprises heating a polyamide, with the addition of a polyfunctional epoxy resin and of a sterically hindered hydroxyphenyl-alkyl-phosphonic ester or monoester, at above the melting point or glass transition point of the polyamide.
U.S. Pat. No. 5,496,920 likewise discloses a process for increasing the molecular weight of polyamides, which comprises heating a polyamide, with the addition of a bismaleimide and of a sterically hindered hydroxyphenyl-alkyl-phosphonic ester or monoester, at above the melting point and/or glass transition point of the polyamide.
The use of reactive additives, for example epoxides, for building up the molecular weight of polycondensates has the disadvantage that relatively long reaction times are quite often necessary. Under such conditions, it is not possible to rule out follow-on reactions, such as discoloration, increased oxidation or uncontrolled crosslinking of the polycondensate, for example. Moreover, commercially available epoxides are often liquid products, especially if a high content of functional groups is necessary, whose addition to the polycondensate employed causes difficulties.
The object of the present invention, therefore, was to provide a system for building up the molecular weight of polycondensates which is highly effective in a relatively short reaction time and which lacks the disadvantages set out above.
WO-A-90/00574 discloses the preparation of polyiminocarbonates starting from bisphenols and dicyanates.
JP-A-04 202 316 discloses a resin composition comprising two polyesters with different glass transition temperatures and a polycyanate. This resin composition is suitable, in contact with sheet steel, for reducing the vibration of the sheet steel (xe2x80x9cdamping sheet steelxe2x80x9d) in a relatively large temperature range, and can also be used as a bonding coat between two steel sheets. In that publication there is no indication that polycyanates are suitable for inducing an increase in the molecular weight of the polyester in the melt.
It has now surprisingly been found that aromatic dicyanates are suitable for increasing the molecular weight and/or viscosity of virgin polycondensate or polycondensate recyclate (i.e. recycled polycondensate) or of a mixture thereof.
The present invention therefore provides a process for increasing the molecular weight and or viscosity of polycondensates which remain thermoformable after the process, which comprises heating a polycondensate, with addition of at least one aromatic dicyanate, at above the melting point or glass transition point of the polycondensate.
A thermoformable polymer is a polymer which is neither crosslinked nor cured in the manner of a thermoset resin. The build-up of molecular weight according to the present invention is referred to in general as chain extension and is disclosed, for example, in EP-A-0 074 337.
The invention also provides a process for increasing the molecular weight and/or viscosity of polycondensates which remain thermoformable after the process, which comprises heating a polycondensate, with the addition of at least one aromatic dicyanate and at least one polyfunctional compound selected from the group consisting of the sterically hindered hydroxyphenyl-alkyl-phosphonic esters and monoesters, diphosphonites or secondary aromatic amines, at above the melting point or glass transition point of the polycondensate.
The present invention also provides a process for increasing the molecular weight and/or viscosity of polycondensates which remain thermoformable after the process, which comprises heating a polycondensate, with the addition (i) of at least one aromatic dicyanate; (ii) of at least one polyfunctional compound selected from the group consisting of the sterically hindered hydroxyphenyl-alkyl-phosphonic esters and monoesters, diphosphonites or secondary aromatic amines; and (iii) of a difunctional epoxide, at above the melting point or glass transition point of the polycondensate.
The increase in molecular weight brings about improvement in the properties of the polycondensates, which becomes evident, for example, in the injection-moulding sector, in the extrusion sector and, in particular, in connection with recyclates. With the aid of the novel process it is possible, in particular, to achieve an increase in molecular weight in polycondensate recyclates from production wastes, as are obtained, for example, during the manufacture of fibers, or from the collection of used industrial components, for example from automotive and electrical applications. This allows recyclates to be passed on for high-grade re-use, for example as high-performance fibers, injection mouldings, extrusion applications or foams. Such recyclates also originate, for example, from industrial or domestic collections of recyclable materials, from production waste, for example from fiber production and trimmings, or from obligatory takeback schemes, for example collections of PET drinks bottles.
A preferred polycondensate is a polycondensate recyclate.
The novel process is of particular interest if the polycondensate is a polyamide, a polyester, a polycarbonate or a copolymer of these polymers.
In addition to polyester, polyamide or polycarbonate, the present invention also embraces the corresponding copolymers and blends, for example PBT/PS, PBT/ASA, PBT/ABS, PBT/PC, PET/ABS, PET/PC, PBT/PET/PC, PBT/PET, PA/PP, PA/PE and PA/ABS. However, in this context it must be borne in mind that the novel process, like all methods which permit substitution reactions, for example transesterification or transamidation, between the blend components, may result in the blend being influenced, i.e. may lead to the formation of copolymeric structures.
Of particular interest is a process wherein the polycondensate is a PBT/PC blend or a blend comprising predominantly PBT/PC or a corresponding recyclate or a blend of a recyclate and a virgin polymer component.
The term polyamides, i.e. both virgin polyamides and polyamide recycdates, refers to aliphatic and aromatic polyamides or copolyamides derived from diamines and dicarboxylic acids and/or from aminocarboxylic acids or their corresponding lactams. Examples of suitable polyamides are PA 6, PA 11, PA 12, PA 46, PA 6.6, PA 6.9, PA 6.10 or PA 6.12, PA 10.12, PA 12.12 and also amorphous polyamides of the types Trogamid PA 6-3-T and Grilamid TR 55. Polyamides, of the type mentioned are generally known and are obtainable commercially
As polyamides use is preferably made of crystalline or partly crystalline polyamides, and especially PA 6 or PA 6.6 or mixtures thereof, and also of recydates based on them, or copolymers thereof.
The polyester, i.e. both virgin polyester and polyester recyclate, can comprise homopolyesters or copolyesters which are composed of aliphatic, cycloaliphatic or aromatic dicarboxylic acids and diols or hydroxycarboxylic acids.
The aliphatic dicarboxylic acids can contain 2 to 40 carbon atoms, the cycloaliphatic dicarboxylic acids 6 to 10 carbon atoms, the aromatic dicarboxylic acids 8 to 14 carbon atoms, the aliphatic hydroxycarboxylic acids 2 to 12 carbon atoms, and the aromatic and cycloaliphatic hydroxycarboxylic acids 7 to 14 carbon atoms.
The aliphatic diols can contain 2 to 12 carbon atoms, the cycloaliphatic diols 5 to 8 carbon atoms, and the aromatic diols 6 to 16 carbon atoms.
The diols referred to as aromatic are those in which two hydroxyl groups are attached to one or to different aromatic hydrocarbon radicals.
It is additionally possible for the polyesters to be branched with small amounts, for example, from 0.1 to 3 mol %, based on the dicarboxylic acids present, of more than difunctional monomers (e.g. pentaerythritol, trimellitic acid, 1,3,5-tri(hydroxyphenyl)benzene, 2,4-dihydroxybenzoic acid or 2-(4-hydroxyphenyl)-2-(2,4dihydroxyphenyl)propane).
In the case of polyesters consisting of at least 2 monomers, these can be distributed randomly, or the polymers can be block copolymers.
Suitable dicarboxylic acids are linear and branched saturated aliphatic dicarboxylic acids, aromatic dicarboxylic acids and cycloaliphatic dicarboxylic acids.
Suitable aliphatic dicarboxylic acids are those with 2 to 40 carbon atoms, examples being oxalic, malonic, dimethylmalonic, succinic, pimelic, adipic, trimethyladipic, sebacic and azelaic acids and dimer acids (dimerization products of unsaturated aliphatic carboxylic acids such as oleic acid), and alkylated malonic and succinic acids, such as octadecylsuccinic acid.
Suitable cycloaliphatic dicarboxylic acids are 1,3-cyclobutanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3- and 1,4-cyclohexanedicarboxylic acid, 1,3- and 1,4-di(carboxylmethyl)cyclohexane and 4,4xe2x80x2-dicyclohexyldicarboxylic acid.
Particularly suitable aromatic dicarboxylic acids are terephthalic acid, isophthalic acid, o-phthalic acid, and 1,3-, 1,4-, 2,6- or 2,7-naphthalenedicarboxylic acid, 4,4xe2x80x2-diphenyldicarboxylic acid, 4,4xe2x80x2-diphenyl sulfone dicarboxylic acid, 4,4xe2x80x2-benzophenonedicarboxylic acid, 1,1,3-trimethyl-5-carboxyl-3-(p-carboxyphenyl)indane, 4,4xe2x80x2-diphenyl ether dicarboxylic acid, bis-(p-carboxyphenyl)methane or bis-(p-carboxyphenyl)ethane.
Preference is given to the aromatic dicarboxylic acids, especially terephthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid.
Other suitable dicarboxylic acids are those containing xe2x80x94COxe2x80x94NHxe2x80x94 groups; they are described in DE-A-2 414 349. Also suitable are dicarboxylic acids containing N-heterocyclic rings, for example those which are derived from carboxyalkylated, carboxyphenylated or carboxybenzylated monoamine-s-triazinedicarboxylic acids (cf. DE-A-2 121 184 and 2 533 675), from mono- or bishydantoins, from unsubstituted or halogenated benzimidazoles, or from parabanic acid. The carboxyalkyl groups in these compounds can contain 3 to 20 carbon atoms.
Suitable aliphatic diols are the linear and branched aliphatic glycols, especially those having 2 to 12, in particular 2 to 6, carbon atoms in the molecule, for example ethylene glycol, 1,2- and 1,3-propylene glycol, 1,2-, 1,3-, 2,3- or 1,4-butanediol, pentylglycol, neopentylglycol, 1,6-hexanediol and 1,12-dodecanediol. An example of a suitable cycloaliphatic diol is 1,4-dihydroxycyclohexane. Examples of further suitable aliphatic diols are 1,4-bis(hydroxymethyl)cyclohexane, aromatic-aliphatic diols, such as p-xylylene glycol or 2,5-dichloro-p-xylylene glycol, 2,2-bis(xcex2-hydroxyethoxyphenyl)propane, and also polyoxyalkylene glycols, such as diethylene glycol, triethylene glycol, polyethylene glycol or polypropylene glycol. The alkylenediols are preferably linear and, in particular, contain 2 to 4 carbon atoms.
Preferred diols are the alkylenediols, 1,4-dihydroxycyclohexane, and 1,4-bis(hydroxymethyl)cyclohexane. Particular preference is given to ethylene glycol, 1,4-butanediols and 1,2- and 1,3-propylene glycol.
Further suitable aliphatic diols are the xcex2-hydroxyalkylated, especially xcex2-hydroxyethylated, bisphenols, such as 2,2-bis[4xe2x80x2-(xcex2-hydroxyethoxy)phenyl]propane. Further bisphenols are mentioned later.
A further group of suitable aliphatic diols are the heterocydic diols described in DE-A 1 812 003, 2 342 432, 2 342 372 and 2 453 326. Examples are N,Nxe2x80x2-bis(xcex2-hydroxyethyl)-5,5-dimethylhydantoin, N,Nxe2x80x2-bis(xcex2hydroxypropyl)-5,5-dimethylhydantoin, methylene bis[N-(xcex2-hydroxyethyl)-5-methyl-5-ethylhydantoin], methylene bis[N-(xcex2hydroxyethyl)-5,5-dimethyl-hydantoin], N,Nxe2x80x2-bis(xcex2-hydroxyethyl)benzimidazolone, N,Nxe2x80x2-bis(xcex2hydroxyethyl)(tetrachloro)-benzimidazolone, or N,Nxe2x80x2-bis(xcex2hydroxyethyl)(tetrabromo)benzimidazolone.
Suitable aromatic diols are monocyclic diphenols and especially bicyclic diphenols carrying a hydroxyl group on each aromatic ring. The term aromatic is preferably taken to mean hydrocarbon-aromatic radicals, for example phenylene or naphthylene. Besides, for example, hydroquinone, resorcinol and 1,5-, 2,6- and 2,7-dihydroxynaphthalene, particular mention should be made of the bisphenols which can be described by the following formulae: 
The hydroxyl groups can be in the m-position, but in particular in the p-positon; Rxe2x80x2 and Rxe2x80x3 in these formulae can be alkyl of 1 to 6 carbon atoms, halogen such as chlorine or bromine, and especially hydrogen atoms. A can be a direct bond, or oxygen, sulfur, xe2x80x94SOxe2x80x94, xe2x80x94SO2xe2x80x94, 
substituted or unsubstituted alkylidene, cycloalkylidene or alkylene.
Examples of unsubstituted or substituted alkylidene are ethylidene, 1,1- or 2,2-propylidene, 2,2-butylidene, 1,1-isobutylidene, pentylidene, hexylidene, heptylidene, octylidene, dichloroethylidene and trichloroethylidene.
Examples of substituted or unsubstituted alkylene are methylene, ethylene, phenylmethylene, diphenylmethylene and methylphenylmethylene. Examples of cycoalkylidene are cyclopentylidene, cyclohexylidene, cycloheptylidene and cyclooctylidene.
Examples of bisphenols are bis(p-hydroxyphenyl) ether or thioether, bis(p-hydroxyphenyl) sulfone, bis(p-hydroxyphenyl)methane, bis(4-hydroxyphenyl)-2,2xe2x80x2-biphenyl, phenylhydroquinone, 1,2-bis(p-hydroxyphenyl)ethane, 1-phenylbis(p-hydroxyphenyl)methane, diphenylbis(p-hydroxyphenyl)methane, diphenylbis(p-hydroxyphenyl)ethane, bis(3,5-dimethyl-4-hydroxyphenyl) sulfone, bis(3,5-dimethyl-4-hydroxyphenyl)-p-diisopropylbenzene, bis(3,5-dimethyl4hydroxyphenyl)-m-diisopropylbenzene, 2,2-bis(3xe2x80x2,5xe2x80x2-dimethyl-4xe2x80x2-hydroxyphenyl)-propane, 1,1- or 2,2-bis(p-hydroxyphenyl)butane, 2,2-bis(p hydroxyphenyl)hexafluoropropane, 1,1-dichloro- or 1,1,1-trichloro-2,2-bis(p-hydroxyphenyl)ethane, 1,1-bis(hydroxyphenyl)cyclopentane and, especially, 2,2-bis(p-hydroxyphenyl)propane (bisphenol A) and 1,1-bis(p-hydroxyphenyl)cyclohexane (bisphenol C).
Examples of suitable polyesters of hydroxycarboxylic acids are polycaprolactone, polypivalolactone or the polyesters of 4-hydroxycyclohexanecarboxylic acid or 4-hydroxybenzoic acid.
Also suitable are polymers which contains predominantly ester linkages, but which can also contain other linkages, such as, for example polyesteramides or polyesterimides.
Polyesters with aromatic dicarboxylic acids have acquired the greatest importance, especially the polyalkylene terephthalates. Preference is therefore given to novel moulding compositions in which the polyester is built up from at least 30 mol %, preferably at least 40 mol %, of aromatic dicarboxylic acids, and at least 30 mol %. preferably at least 40 mol %, of alkylenediols having preferably 2 to 12 carbon atoms, based on the polyester.
In particular in this case the alkylenediol is linear and contains 2 to 6 carbon atoms, for as example ethylene or tri-, tetra- or hexamethylene glycol, and the aromatic dicarboxylic acid is terephthalic and/or isophthalic acid.
The novel process is likewise of particular interest if the polycondensate is a polyester.
Particularly suitable polyesters are PET, PBT or PEN (polyethylene naphthylate) and corresponding copolymers, especial preference being given to PET and its copolymers. The process also acquires particular importance in connection with PET recyclates, which are obtained, for example, from bottle collections, for example from collections by the drinks industry. These materials consist, preferably, of terephthalic acid, 2,6naphthalene-dicarboxylic acid and/or isophthalic acid in combination with ethylene glycol and/or 1,4-bis(hydroxymethyl)cyclohexane.
The term polycarbonate (PC) refers both to virgin polycarbonate and to polycarbonate recyclate. PC is obtained, for example, from bisphenol A and phosgene or a phosgene analogue, such as trichloromethyl chloroformate, triphosgene or diphenylcarbonate, by condensation, in the latter case generally with addition of a suitable transesterification catalyst, for example a borohydride, an amine, such as 2-methylimidazole, or a quatemary ammonium salt; besides bisphenol A, other bisphenol components can additionally be used, and monomers which are halogenated in the benzene ring can also be employed. Particularly suitable bisphenol components which may be mentioned are 2,2-bis(4xe2x80x2-hydroxyphenyl)propane (bisphenol A), 2,4xe2x80x2-dihydroxydiphenylmethane, bis(2-hydroxyphenyl)methane, bis(4-hydroxyphenyl)methane, bis(4-hydroxy-5-propylphenyl)-methane, 1,1-bis(4xe2x80x2-hydroxyphenyl)ethane, bis(4-hydroxyphenyl)cyclohexylmethane, 2,2-bis(4xe2x80x2-hydroxyphenyl)-1-phenylpropane, 2,2-bis(3xe2x80x2,5xe2x80x2-dimethyl4xe2x80x2-hydroxyphenyl)propane, 2,2-bis(3xe2x80x2,5xe2x80x2-dibromo-4xe2x80x2-hydroxyphenyl)propane, 2,2-bis(3xe2x80x2,5xe2x80x2-dichloro-4xe2x80x2-hydroxyphenyl)-propane, 1,1-bis(4xe2x80x2-hydroxyphenyl)-cyclododecane, 1,1-bis(3xe2x80x2,5xe2x80x2-dimethyl-4xe2x80x2-hydroxyphenyl)-cyclododecane, 1,1-bis(4xe2x80x2-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 1,1-bis(4xe2x80x2-hydroxy-phenyl)-3,3,5,5-tetramethylcyclohexane, 1,1-bis(4xe2x80x2-hydroxyphenyl)-3,3,5-trimethylcyclo-pentane and the other bisphenols indicated further above. Furthermore, the polycarbonates may also be branched as a result of appropriate amounts of monomers having a functionality of more than two (examples as given further above for the polyesters).
The novel process is also of particular interest if the polycondensate is a polycarbonate.
The polycondensate copolymers or blends which can be used in the novel process are prepared in a conventional manner from the starting polymers. The polyester component is preferably PBT and the PC component is preferably a PC based on bisphenol A. The polyester:PC ratio is preferably from 95:5 to 5:95, particular preference being given to a ratio in which one component makes up at least 75%.
The invention acquires particular importance in connection with polycondensate recyclates as obtained from production waste, collections of recyclable material, or as a result of obligatory takeback schemes, for example in the automotive, industry, in the electrical sector, compact discs or twin-wall sheets. The polycondensate recyclates have suffered thermal and/or hydrolytic damage in a variety of ways. Moreover, these recyclates may also include minor amounts of admixed plastics having a different structure, for example polyolefins, polyurethanes, ABS or PVC. Furthermore, these recyclates can also include customary impurities, for example residues of dyes, adhesives, contact media or paints, traces of metal, traces of water, traces of service fluids, or inorganic salts.
Aromatic dicyanates in the context of this invention are known, for example, from U.S. Pat. No. 3,491,060 and are, preferably, compounds of the formula I 
in which
X is a direct bond, oxygen, sulfur, xe2x80x94SOxe2x80x94, xe2x80x94SO2xe2x80x94, 
xe2x80x83C2-C18alkylene, C2-C18alkenylene or 
R1, R2, R3 and R4 independently of one another are hydrogen, C1-C25alkyl, C5-C12cycloalkyl, unsubstituted or C1-C4alkyl-substituted phenyl; C7-C9phenylalkyl, hydroxyl, C1-C25alkoxy or xe2x80x94Oxe2x80x94CN, with the proviso that at least one of the radicals R1, R2, R3 and R4 is xe2x80x94Oxe2x80x94CN, R5, R6, R7 and R8 independently of one another are hydrogen, C1-C25alkyl, C5-C12cyloalkyl, or unsubstituted or C1-C4alkyl-substituted phenyl; C7-C9phenylalkyl, hydroxyl, C1-C25alkoxy xe2x80x94Oxe2x80x94CN, with the proviso that at least one of the radicals R5, R6, R7and R8 is xe2x80x94Oxe2x80x94CN, R9 and R10 independently of one another are hydrogen, C1-C12alkyl, trifluoromethyl or phenyl, or R9 and R10, together with the carbon atom to which they are attached, form a C5-C8cycloalkylidene ring which is unsubstituted or is substituted by 1 to 3 C1-C4alkyls; and R11 is hydrogen or C1-C12alkyl.
C2-C18alkylene is a branched or unbranched radical such as, for example, ethylene, propylone, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, docamethylene, dodecamethylene or octadecamethylene. Preference is given to C2-C12alkylene, especially C2-C8alkylene, for example C2-C4alkylene.
C2-C18alkenylene is a branched or unbranched radical having one or more Cxe2x80x94C double bonds, such as, for example, vinylene, methylvinylene, octenylethylene or dodecenylethylene. Preference is given to C2-C12alkenylene, especially C2-C8alkenylene, for example C2-C4alkenylene.
Alkyl having up to 25 carbon atoms is a branched or unbranched radical such as, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, 2-ethylbutyl, n-pentyl, isopentyl, 1-methylpentyl, 1,3-dimethylbutyl, n-hexyl, 1-methylhexyl, n-heptyl, isoheptyl, 1,1,3,3tetramethylbutyl, 1-methylheptyl, 3-methylheptyl, n-octyl, 2-ethylhexyl, 1,1,3-trimethylhexyl, 1,1,3,3-tetramethylpentyl, nonyl, decyl, undecyl, 1-methylundecyl, dodecyl, 1,1,3,3,5,5-hexamethylhexyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl or docosyl. One of the preferred definitions of R1, R2, R4, R5, R6, R7 and R8 is, for example, C1-C18alkyl, especially C1-C12alkyl, e.g. C1-C8alkyl. A preferred definition of R9 and R10 is, for example, C1-C8alkyl, especially C1-C4alkyl, e.g. methyl. A particularly preferred definition of R11 is, for example, C1-C8alkyl, especially C1-C4alkyl, e.g. methyl, ethyl, n-propyl or n-butyl.
C5-C12cycloalkyl is, for example, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl or cyclododecyl. A preferred definition of R1, R2, R3, R4, R5, R6, R7 and R8 is, for example, C5-C8cycloalkyl, especially C5-C7cyloalkyl, e.g. cyclohexyl.
C1-C4alkyl-substituted phenyl, which preferably contains 1 to 3, especially 1 or 2 alkyl groups, is, for example, o-, m- or p-methylphenyl, 2,3dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2-methyl-6ethylphenyl, 4tert-butylphenyl or 2-ethylphenyl, 2,6-diethylphenyl.
C7-C9phenylalkyl is, for example, benzyl, xcex1-methylbenzyl or xcex1,xcex1-dimethylbenzyl. Benzyl is preferred.
Alkoxy having up to 25 carbon atoms is a branched or unbranched radical such as, for example, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, pentoxy, isopentoxy, hexyloxy, heptyloxy, octyloxy, decyloxy, tetradecyloxy, hexadecyloxy or octadecyloxy. A preferred definition of R1, R2, R3, R4, R5, R6, R7 and R8 is, for example, C1-C18alkoxy, especially C1-C12alkoxy, e.g. C1-C8alkoxy. Methoxy is particularly preferred.
A C1-C4alkyl-substituted C5-C8cycloalkyliden ring, which preferably contains 1 to 3, especially 1 or 2 branched or unbranched alkyl groups, is, for example, cyclopentylidene, methylcyclopentylidene, dimethylcyclopentylidene, cyclohexylidene, methylcyclohexylidene, dimethylcyclohexylidene, trimethylcyclohexylidene, tert-butylcyclohexylidene, cycloheptylidene or cyclooctylidene. Preference is given to cyclohexylidene and 4-tert-butylcyclohexylidene.
Particular preference is given to the compounds of the formula I in which
X is a direct bond, oxygen, 
xe2x80x83C2-C12alkylene or C2-C12alkenylene,
R1, R2, R3 and R4 independently of one another are hydrogen, C1-C18alkyl, C5-C8cycloalkyl, phenyl, benzyl, C1-C18alkoxy or xe2x80x94Oxe2x80x94CN, with the proviso that at least one of the radicals R1, R2, R3 or R4 is xe2x80x94Oxe2x80x94CN,
R5, R6, R7 and R8 independently of one another are hydrogen, C1-C18alkyl, C5-C8cycloalkyl, phenyl, benzyl, C1-C18alkoxy or xe2x80x94Oxe2x80x94CN, with the proviso that at least one of the radicals R5, R6, R7 or R8 is xe2x80x94Oxe2x80x94CN, and
R9 and R10 independently of one another are hydrogen, C1-C8alkyl, trifluoromethyl or phenyl, or R9 and R10, together with the carbon atom to which they are attached, form a C5-C8cycloalkylidene ring.
Examples of particularly preferred aromatic dicyanates of the formula I are the compounds of the formula Ia, Ib, Ic, Id, Ie or If 
The compound of the formula Ia is also referred to as BPC (bisphenol A dicyanate). The compounds of the formulae Ia to If are obtainable commercially under the following names: AroCy(copyright)B-10 (Rhone-Poulenc, compound of the formula Ia); AroCy(copyright) M-10 (Rhone-Poulenc, compound of the formula Ib); AroCy(copyright) F-10 (Rhone-Poulenc, compound of the formula Ic); AroCy(copyright) L-10 (Rhone-Poulenc, compound of the formula Id); RTX(copyright) 366 (Rhone-Poulenc, compound of the formula Ie); and XU(copyright) 71787 (Dow Chemical Co., compound of the formula If).
Of particular interest are the aromatc dicyanates of the formula I in which
R1 and R5 are hydrogen,
R2, R4, R6 and R8 are hydrogen or methyl, and
R3 and R7 are xe2x80x94Oxe2x80x94CN.
Of specific interest are the compounds of the formula I in which
X is a direct bond, 
R1 is hydrogen,
R2 is hydrogen or C1-C4alkyl,
R3 is xe2x80x94Oxe2x80x94CN,
R4 is hydrogen or C1-C4alkyl,
R5 is hydrogen,
R6 is hydrogen or C1-C4alkyl,
R7 is xe2x80x94Oxe2x80x94CN,
R8 is hydrogen or C1C4alkyl, and
R9 and R10 independently of one another are hydrogen, methyl or trifluoromethyl.
Very particular preference is given to the compounds of the formula I in which 
R1 and R2 are hydrogen,
R3 is xe2x80x94Oxe2x80x94CN,
R4, R5 and R6 are hydrogen,
R7 is xe2x80x94Oxe2x80x94CN,
R8 is hydrogen, and
R9 and R10 independently of one another are hydrogen or methyl.
Particularly preferred aromatic dicyanates are those of the formula Ia and Id.
Based on 100 parts of polycondensate, preferably from 0.01 to 5 parts, particularly preferably from 0.02 to 2 parts and, in particular, from 0.05 to 1 part of the aromatic dicyanat are employed.
Polyfunctional compounds from the class of the sterically hindered hydroxyphenyl-alkyl-phosphonic esters and monoesters have been disclosed, for example, in U.S. Pat. No. 4,778,840 and are, for example, compounds of the formula II 
in which
R21 is isopropyl, tert-butyl, cyclohexyl or cyclohexyl which is substituted by 1 to 3 C1-C4alkyl groups,
R22 is hydrogen, C1-C4alkyl, cyclohexyl or cyclohexyl which is substituted by 1 to 3 C1-C4)alkyl groups,
R23 is C1-C20alkyl, or unsubstituted or C1-C4alkyl-substituted phenyl or naphthyl,
R24 is hydrogen, C1-C20alkyl, unsubstiuted or C1-C4alkyl-substituted phenyl or naphthyl; or is             M              r        +              r    ,
Mr+ is an r-valent metal cation,
n is 1, 2, 3, 4, 5 or 6, and
r is 1, 2 or 3.
Where substituents are alkyl having up to 20 carbon atoms, the relevant radicals are those such as methyl, ethyl, propyl, butyl, pentyl, hexyl and octyl, stearyl and corresponding branched isomers. A preferred definition of R23 and R24 is C1-C12alkyl, especially C1-C9alkyl, e.g. C2-C4alkyl.
C1-C4alkyl-substituted phenyl or naphthyl, which preferably contains 1 to 3, especially 1 or 2 alkyl groups, is, for example. o-, m- or p-methylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2-methyl-6-ethylphenyl, 4-tert-butylphenyl, 2-ethylphenyl, 2,6-diethylphenyl, 1-methylnaphthyl, 2-methylnaphthyl, 4-methylnaphthyl, 1,6-dimethylnaphthyl or 4-tert-butylnaphthyl.
C1-C4alkyl-substituted cyclohexyl, which preferably contains 1 to 3, especially 1 or 2 branched or unbranched alkyl group radicals, is, for example, cyclopentyl, methylcyclopentyl, dimethylcyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, trimethylcyclohexyl or tert-butylcyclohexyl.
A mono-, di- or trivalent metal cation is preferably an alkali metal, alkaline earth metal, heavy metal or aluminium cation, for example Na+, K+, Mg++, Ca++, Ba++, Zn++or Al+++, Ca++ is especially preferred.
Preferred compounds of the formula II are those having at least one tert-butyl group as radical R21 or R22. Very particular preference is given to compounds in which R21 and R22 are both tert-butyl.
n is preferably 1 or 2, especially 1.
Very particularly preferred stericaily hindered hydroxyphenyl-alkyl-phosphonic esters and monoesters are the compounds of the formulae IIa and IIb. 
The compound of the formula IIa is obtainable commercially under the name Irganox(copyright)1222 (Ciba-Geigy) and that of the formula IIb under the name Irganox(copyright)1425 (Ciba-Geigy).
Based on 100 parts of polycondensate, preferably from 0.01 to 5 parts, particularly preferably from 0.02 to 2 parts and, in particular, from 0.05 to 1 part of a sterically hindered hydroxyphenyl-alkyl-phosphonic ester or monoester are employed.
Polyfunctional compounds from the class of the diphosphonites are known, for example, from GBA-2 247 241 and are, for example, compounds of the formula III 
in which
R31, R32, R33, R34, R35, R36, R37, R38, R39 and R40 independently of one another are hydrogen or C1-C8alkyl,
Y is 1,4-phenylene, 1,3phenylene, 
Z is a direct bond, phenylene, oxygen, sulfur, xe2x80x94SOxe2x80x94, xe2x80x94SO2xe2x80x94 or 
Alkyl having up to 8 carbon atoms is a branched or unbranched radical such as, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, 2-ethylbutyl, n-pentyl, isopentyl, 1-methylpentyl, 1,3-dimethylbutyl, n-hexyl, 1-methylhexyl, n-heptyl, isoheptyl, 1,1,3,3-tetramethylbutyl, 1-methylheptyl, 3-methylheptyl, n-octyl, tert-octyl or 2-ethylhexyl. One of the preferred definitions of R31, R32, R33, R34, R35, R36,R37, R38, R39 and R40 is, for example, C1-C8alkyl, especially C1-C4alkyl, e.g. methyl or tert-butyl.
Preference is given to the compounds of formula III in which at least two of the radicals R31, R32, R33, R34 and R35 and at least two of the radicals R36, R37, R38, R39 and R40 are hydrogen.
Also of interest are the compounds of formula III, in which R32, R34, R35, R37, R39 and R40 are hydrogen.
Particular preference is given to the compounds of the formula III in which 
Very particular preference is given to tetrakis(2,4-di-tert-butylphenyl) 4,4xe2x80x2-biphenylene-diphosphonite (Irgafos(copyright)PEPQ, Ciba-Geigy) of the formula IIIa 
Based on 100 parts of polycondensate, preferably from 0.01 to 5 parts, particularly preferably from 0.02 to 2 parts and. In particular from 0.05 to 1 part of a diphosphonite are employed.
Compounds from the class of the secondary aromatic amines are known, for example, from R. Gxc3xa4chter and H. Mxc3xcller, Hanser Vertag, xe2x80x9cPlastics Additives Handbook, 3rd Ed.xe2x80x9d, page 44 to 45 (1990) and are, for example, compounds of the formula IV 
in which
R41 is hydrogen or C1-C25alkyl,
R42 is hydrogen, C1-C25alkyl or benzyl,
R43 is hydrogen, C1-C25alkyl, C5-C12cycloalkyl, benzyl, xcex1-methylbenzyl or xcex1,xcex1-dimethylbenzyl;
or R42 and R43 together form a divalent group 
R44 is hydrogen, C1-C25alkyl or benzyl,
R45 is hydrogen or C1-C25alkyl,
R46 is hydrogen, C1-C25alkyl or benzyl,
R47 is hydrogen, C1-C25alkyl, C5-C12cyloalkyl, benzyl, xcex1-methylbenzyl, xcex1,xcex1-dimethylbenzyl or 
xe2x80x83or R45 and R47 together form a divalent group 
R48 is hydrogen, C1-C25alkyl or benzyl,
R49 is hydrogen or C1-C25alkyl, and
R50 is C5-C12cycloalkyl, 
Alkyl having up to 25 carbon atoms is a branched or unbranched radical such as, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, 2-ethylbutyl, n-pentyl, isopentyl, 1-methylpentyl, 1,3-dimethylbutyl, n-hexyl, 1-methylhexyl, n-heptyl, isoheptyl, 1,1,3,3-tetramethylbutyl, 1-methylheptyl, 3-methylheptyl, n-octyl, 2-ethylhexyl, 1,1,3-trimethylhexyl, 1,1,3,3-tetramethylpentyl, nonyl, decyl, undecyl, 1-methylundecyl, dodecyl, 1,1,3,3,5,5-hexamethylhexyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl or docosyl. One of the preferred definitions of R41, R42, R44, R45, R46 and R48 is, for example, C1-C18alkyl, especially C1-C12alkyl, e.g. C1-C8-alkyl. A particularly preferred definition of R43 and R47 is, for example, C1-C18alkyl, especially C1C12alkyl, e.g. C4-C12alkyl. A particularly preferred definition of R43 and R47 is C4-C10alkyl, especially C4-C8alkyl, e.g. tert-butyl or tertoctyl.
C5-C12cycloalkyl is, for example, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl or cyclododecyl. A preferred definition of R43, R47 and R50 is, for example, C5-C8cycloalkyl, especially C5-C7cycloalkyl, e.g. cyclohexyl.
Particular preference is given to the compounds of the formula IV in which
R41 and R42 independently of one another are hydrogen or C1-C18alkyl,
R43 is hydrogen, C1-C18alkyl, C5-C8cycloalkyl, benzyl, xcex1-methylbenzyl or xcex1xcex1-dimethylbenzyl;
or R42 and R43 together form a divalent group 
R44, R45 and R46 independently of one another are hydrogen or C1-C18alkyl,
R47 is hydrogen, C1-C18alkyl, C5-C8cycloalkyl, benzyl, xcex1-methylbenzyl, xcex1,xcex1-dimethylbenzyl or 
xe2x80x83or R48 and R47 together form a divalent group 
R48 and R49 independently of one another are hydrogen or C1-C18alkyl, and
R50 is C5-C8cycloalkyl, 
Of particular Interest are the secondary aromatic amines of the formula IV, in which R41, R44, R45, R46 and R48 are hydrogen.
Of specific interest are the compounds of the formula IV, in which
R41 and R42 are hydrogen,
R43 is hydrogen, C4-C12alkyl, cydohexyl, benzyl, xcex1-methylbenzyl or xcex1,xcex1-dimethylbenzyl; or
R42 and R43 together form a divalent group 
R44, R45 and R46 are hydrogen,
R47 is hydrogen, C4-C12alkyl, cyclohexyl, benzyl, xcex1-methylbenzyl, xcex1,xcex1-dimethylbenzyl or 
R48 and R49 is hydrogen, and
R50 is cydohexyl, phenyl or xcex2-naphthyl.
Very particular preference is given to the secondary aromapic amines of formulae IVa, IVb, IVc, IVd, IVe and IVf. 
An especially preferred secondary aromatic amine is the compound of the formula IVe [4,4xe2x80x2-di-tert-octyldiphenylamine, Irganox(copyright) 5057 (Ciba-Geigy)].
The compounds of the formula IV are known and some are commercially available or can be prepared as described in R. Gxc3xa4chter and H. Mxc3xcller, Hanser Verlag, xe2x80x9cPlastics Additives Handbook, 3rd Ed.,xe2x80x9d page 44 to 45 (1990) in analogy to the literature references cited therein.
Based on 100 parts of polycondensate, preferably from 0.01 to 5 parts, particularly preferably from 0.02 to 2 parts and, in particular, from 0.05 to 1 part of a secondary aromatic amine are employed.
Difunctional epoxides in the context of this invention can have an aliphatic, aromatic, cycloaliphatic, araliphatic or heterocydic structure; they indude epoxide groups as side groups or these groups form part of an alicyclic or heterocydic ring system. The epoxide groups are preferably attached as glycidyl groups to the remainder of the molecule by way of ether or ester linkages, or the compounds are N-glycidyl derivatives of heterocyclic amines, amides or imides. Epoxides of these types are generally known and commercially available.
The epoxides contain two epoxide radicals, for example those of the formula V 
which are attached directly to carbon, oxygen, nitrogen or sulfur atoms and in which R61 and R63 are both hydrogen, R62 is hydrogen or methyl and m is 0; or in which R61 and R63 together are xe2x80x94CH2CH2xe2x80x94 or xe2x80x94CH2CH2CH2xe2x80x94, R62 is then hydrogen and m is 0 or 1.
1. Diglycidyl and di(xcex2-methylglycidyl) esters obtainable by reacting a compound with two carboxyl groups in the molecule and epichlorohydrin and/or glycerol dichlorohydrin and/or xcex2-methylepichlorohydrin. The reaction is expediently carried out in the presence of bases.
As compounds of two carboxyl groups in the molecule, aliphatic dicarboxylic acids can be used. Examples of these dicarboxylic acids are glutaric acid, adipic acid, pimelic acid, suboric acid, azelaic acid, sebacic acid or dimerized or trimerized linoleic acid.
It is however also possible to employ cycloaliphatic dicarboxylic acids such as, for example, tetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, hexahydrophthalic acid or 4-methylhexahydrophthalic add.
Furthermore, aromatic dicarboxylic adds, for example phthalic acid or isophthalic add, can be used.
2. Diglycidyl or di(xcex2-methylglycidyl) ethers obtainable by reacting a compound with two free alcoholic hydroxyl groups and/or phenolic hydroxyl groups and a suitably substituted epichlorohydrin under alkaline conditions, or in the presence of an acidic catalyst with subsequent alkali treatment.
Ethers of this type are derived, for example, from acyclic alcohols, such as ethylene glycol, diethylene glycol and higher poly(oxyethylene) glycols, propane-1,2-diol, or poly(oxypropylene) glycols, propane-1,3-diol, butane-1,4-diol, poly(oxytetramethylene) glycols, pentane-1,5-diol, hexane-1,6-diol, sorbitol, and from polyepichlorohydrins.
However, they are also derived, for example, from cycloaliphatic alcohols such as 1,3- or 1,4-dihydroxycyclohexane, bis(4hydroxycyclohexyl)methane, 2,2-bis(4-hydroxycyclohexyl)-propane or 1,1-bis(hydroxymethyl)cyclohex-3-ene, or they possess aromatic nuclei, such as N,N-bis(2-hydroxyethyl)aniline or p,pxe2x80x2-bis(2-hydroxyethylamino)diphenylmethane.
The epoxides can also be derived from mononuclear phenols, such as, for example, from resorcinol, pyrocatechol or hydroquinone; or they are based on polynuclear phenols such as, for example, on 4,4xe2x80x2-dihydroxybiphenyl, bis(4-hydroxphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, 4,4xe2x80x2-dihydroxydiphenylsulfone, 9,9xe2x80x2-bis(4-hydroxyphenyl)fluorene, or on condensation products of phenols with formaldehyde that are obtained under acidic conditions, such as phenol novolaks.
3. Di-(N-glycidyl) compounds are obtainable, for example, by dehydrochlorination of the reaction products of epichlorohydrin with amines containing two amino hydrogen atoms. Examples of these amines are aniline, toluidine, n-butylamine, bis(4-aminophenyl)methane, m-xylylenediamine or bis(4-methylaminophenyl)methane.
Also included among the di(N-glycidyl) compounds, however, are N,Nxe2x80x2-diglyddyl derivatives of cycloalkyleneureas, such as ethyleneurea or 1,3-propyleneurea, and N,Nxe2x80x2-diglycidyl derivatives of hydantoins such as of 5,5-dimethylhydantoin.
4. Di(S-glycidyl) compounds, such as di-S-glycidyl derivatives derived from dithiols, such as, for example, ethane-1,2-dithiol or bis(4-mercaptomethylphenyl)ether.
5. Epoxides with a radical of the formula V in which R61 and R63 together are xe2x80x94CH2CH2xe2x80x94 and m is 0 are, for example, bis(2,3-epoxycyclopentyl)ether, 2,3-epoxycyclopentyl glycidyl ether or 1,2-bis(2,3-epoxycyclopentoxy)ethane; an example of epoxides with a radical of the formula V in which R61 and R63 together are xe2x80x94CH2CH2xe2x80x94 and m is 1 is (3xe2x80x2,4xe2x80x2-epoxy-6xe2x80x2-methylcyclohexyl)methyl 3,4-epoxy-6-methylcyclohexanecarboxylate.
Owing, for example, to their preparation process, the abovementioned difunctional epoxides may include small amounts of mono- or trifunctional fractions.
Predominanty, use is made of diglycidyl compounds having aromatic structures.
If desired, it is also possible to employ a mixture of epoxides of different structures.
On the other hand, tri- and polyfunctional epoxides can be added supplementarily in order, if desired, to obtain branching. Examples of such epoxides are:
a) liquid bisphenol A diglyddyl ethers, such as Araldit(copyright)GY 240, Araldit(copyright)GY 250, Araldit(copyright)GY 260, Araldit(copyright)GY 266, Araldit(copyright)GY 2600 or Araldit(copyright)MY 790;
b) solid bisphenol A diglycidyl ethers, such as Araldit(copyright)GT 6071, Araldit(copyright)GT 7071, Araldit(copyright)GT 7071, Araldit(copyright)GT 7072, Araldit(copyright)GT 6063, Araldit(copyright)GT 7203, Araldit(copyright)GT 6064, Araldit(copyright)GT 7304, Araldit(copyright)GT 7004, Araldit(copyright)GT 6084, Araldit(copyright)GT 1999, Araldit(copyright)GT 7077, Araldit(copyright)GT 6097, Araldit(copyright)GT 7097, Araldit(copyright)GT 7008, Araldit(copyright)GT 6099, Araldit(copyright)GT 6608, Araldit(copyright)GT 6609 or Araldit(copyright)GT 6610;
c) liquid bisphenol F diglycidyl ethers, such as Araldit(copyright)GY 281, Araldit(copyright)GY 282, Araldit(copyright)PY 302, or Araldit(copyright)PY 306;
d) solid polyglycidyl ethers of tetraphenylethane, such as CG Epoxy Resin(copyright)0163;
e) solid and liquid polyglycidyl ethers of phenol-formaldehyde novolak such as EPN 1138, EPN 1139, GY 1180, PY 307;
f) solid and liquid polyglycidyl ethers of o-cresol-tormaldehyde novolak, such as ECN 1235, ECN 1273, ECN 1280, ECN 1299;
g) liquid glycidyl ethers of alcohols, such as Shell(copyright)Glycidylether 162, Araldit(copyright)DY 0390 or Araldit(copyright)DY 0391;
h) liquid glycidyl esters of carboxylic acids, such as Shell(copyright)Cardura E terephthalic ester, trimellitic ester. Araldit(copyright)PY 284 or mixtures of aromatic glycidyl esters, for example Araldit(copyright)PT 910;
i) solid heterocyclic epoxy resins (triglycidyl isocyanurate) such as Araldit(copyright)PT 810;
j) liquid cycloaliphatc epoxy resins such as Araldit(copyright)CY 179.
k) liquid N,N,O-triglycidyl ethers of p-aminophenol, such as Araldit(copyright)MY 0510;
l) tetraglycidyl-4xe2x80x944xe2x80x2-methylenebenzamine or N,N,Nxe2x80x2,Nxe2x80x2-tetraglycidyldiaminophenylmethane, such as Araldit(copyright)MY 720, Araldit(copyright)MY 721.
Particularly preferred difunctional epoxides are diglycidyl ethers based on bisphenols such as, for example, on 2,2-bis(4hydroxyphenyl)propane (bisphenol A), bis(4-hydroxyphenyl)-sulfone (bisphenol S) or mixtures of bis(ortho/para-hydroxyphenyl)methane (bisphenol F).
Very particular preference is given to epoxides of the bisphenol A diglycidyl ether type, for example: Araldit(copyright)GT 6071, GT 7071, GT 7072, GT 6097 and GT 6099 or epoxides of the bisphenol F type, such as Araldit(copyright)GY 281 or PY 306. Of very special interest is an epoxide of the bisphenol A diglycidyl ether type, such as Araldit(copyright)T 6071, for example.
Based on 100 parts of polycondensate, preferably from 0.01 to 5 parts, particularly preferably from 0.02 to 2 parts and, in particular from 0.05 to 1 part of a difunctional epoxide are employed.
The process can be carried out in any vessels which can be heated and are fitted with a stirring device. These may, for example, be closed apparatus from which atmospheric oxygen is excluded, working for example under an inert gas atmosphere such as nitrogen, or else with vacuum degassing. The process is preferably conducted in an extruder.
The polycondensate that is to be heated and the novel additives are usually charged to the apparatus at the beginning of heating; however, subsequent metered addition of the novel additives to the polycondensate is also possible, it being possible for the mixture of the additives or else the individual components to be added in any desired sequence. Heating at above the melting point or glass transition point is generally carried out until the novel additives are homogeneously distributed. Homogeneous distribution can take place, for example, by means of stirring or kneading in an extruder. The temperature here depends on the polycondensate used. In the case of crystalline polycondensates, it is preferred to operate in the range between melting point and a temperature about 50xc2x0 C. above the melting point. In the case of amorphous polycondensates, the process is expediently carried out, for instance, In the region of 50xc2x0 C. and 150xc2x0 C. above the respective glass transition temperature.
For their addition, the novel additives can independently of one another be present in the form of a liquid, powder or granules, or in compacted form, or else on a substrate material, such as silica gel, together with a polymer powder or wax, for example a polyethylene wax, or as a concentrate, for example in a masterbatch.
The amount of additives depends on the initial molecular weight of the polycondensate and on the desired final molecular weight.
The novel process has the advantage that the increase in molecular weight and/or viscosity takes place within short reaction times, and the additives can be added in solid form. The novel process also has the advantage that the polycondensate undergoes no additional discoloration. The combination of (i) aromatic dicyanates with (ii) polyfunctional compounds selected from the class of the sterically hindered hydroxyphenyl-alkyl-phosphonic esters and monoesters, diphosphites and secondary aromatic amines leads synergistically to the build-up of the molecular weight of virgin polycondensate or polycondensate recyclate, with retention of the linear chain structure.
In addition to the additives described above, stabilizers can be added to the polycondensate. These stabilizers are generally known to the skilled worker and are chosen depending on the specific requirements regarding the end product. In particular it is possible to add light stabilizers or else antioxidants (R. Gxc3xa4chter, H. Mxc3xcller, Hanser Verlag, xe2x80x9cPlastics Additives Handbook, 3rd Ed.,xe2x80x9d especially pages 82 to 85 and 255 to 258 (1990)). Among these, those which may be mentioned as particularly suitable are:
1. antioxidants
1.1. Esters of xcex2-(3,5-di-tert-butyl4-hydroxphenyl)propionic acid with mono- or polyhydric alcohols, e.g, with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,Nxe2x80x2-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.
1.2. Esters of xcex2-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, noctanol, i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,Nxe2x80x2-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicydo[2.2.2]octane.
1.3. Esters of xcex2-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,Nxe2x80x2-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicycdo[2.2.2]octane.
1.4. Esters of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,Nxe2x80x2-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.
1.5. Amides of xcex2-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid e.g. N,Nxe2x80x2-bis(3,5-di-tertbutyl-4-hydroxyphenylpropionyl)hexamethylenediamide, N,Nxe2x80x2-bis(3,5di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamide, N,Nxe2x80x2-bis(3,5-di-tert-butyl4-hydroxyphenylpropionyl)-hydrazide, N,Nxe2x80x2-bis[2-(3-[3,5-di-tert-butyl-4hydroxyphenyl]propionyloxy)ethyl]oxamide (Naugard(copyright)XL-1 supplied by Uniroyal).
1.6. Tocopherols, for example xcex1-tocopherol, xcex2-tocopherol, xcex3-tocopherol, xcex4-tocopherol and mixtures thereof (vitamin E).
Among these, preferred antioxidants are those of the type Irganox(copyright)1098 (N,Nxe2x80x2-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamine) or Irganox(copyright)245 (ester of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with triethylene glycol), preferably in combination with aromatic phosphites or phosphonites (see item 3).
2. UV Absorbers and Light Stabilisers
2.1. 2-(2xe2x80x2-Hydroxyohenyl)benzotriazoles, for example 2-(2xe2x80x2-hydroxy-5xe2x80x2-methylphenyl)-benzotriazole, 2-(3xe2x80x2,5xe2x80x2-di-tert-butyl-2xe2x80x2-hydroxyphenyl)benzotriazole, 2-(5xe2x80x2-tert-butyl-2xe2x80x2-hydroxyphenyl)benzotriazole, 2-(2xe2x80x2-hydroxy-5xe2x80x2-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole, 2-(3xe2x80x2,5xe2x80x2-di-tert-butyl-2xe2x80x2-hydroxyphenyl)-5chloro-benzotriazole, 2-(3xe2x80x2-tert-butyl-2xe2x80x2-hydroxy-5xe2x80x2-methylphenyl)-5-chloro-benzotriazole, 2-(3xe2x80x2-sec-butyl-5xe2x80x2-tert-butyl-2xe2x80x2-hydroxyphenyl)benzotriazole, 2-(2xe2x80x2-hydroxy4xe2x80x2-octyloxyphenyl)benzotriazole, 2-(3xe2x80x2,5xe2x80x2-di-tert-amyl-2xe2x80x2-hydroxyphenyl)benzotriazole, 2-(3xe2x80x2,5xe2x80x2bis-(xcex1,xcex1-dimethylbenzyl)-2xe2x80x2-hydroxyphenyl)benzotriazole, 2-(3xe2x80x2-tert-butyl-2xe2x80x2-hydroxy-5xe2x80x2-(2-octyloxycarbonylethyl)phenyl)-5-chloro-benzotriazole, 2-(3xe2x80x2-tert-butyl-5xe2x80x2-[2-(2-ethylhexyloxy)-carbonylethyl]-2xe2x80x2-hydroxyphenyl)-5-chloro-benzotriazole, 2-(3xe2x80x2-tert-butyl-2xe2x80x2-hydroxy-5xe2x80x2-(2-methoxycarbonylethyl)phenyl)-5chloro-benzotriazole, 2-(3xe2x80x2-tert-butyl-2xe2x80x2-hydroxy-5xe2x80x2-(2-methoxycarbonylethyl)phenyl)benzotriazole, 2-(3xe2x80x2-tert-butyl-2xe2x80x2-hydroxy-5xe2x80x2-(2-octyloxycarbonylethyl)phenyl)benzotriazole, 2-(3xe2x80x2-tert-butyl-5xe2x80x2-[2-(2-ethylhexyloxy)carbonylethyl]-2xe2x80x2-hydroxyphenyl)benzotriazole, 2-(3xe2x80x2-dodecyl-2xe2x80x2-hydroxy-5xe2x80x2-methylphenyl)benzotriazole, 2-(3xe2x80x2-tert-butyl-2xe2x80x2-hydroxy-5xe2x80x2-(2-isooctyloxycarbonylethyl)phenylbenzotriazole, 2,2xe2x80x2-methylene-bis-[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazole-2-ylphenol]; the transesterification product of 2-[3xe2x80x2-tert-butyl-5xe2x80x2-(2-methoxycarbonylethyl)-2xe2x80x2-hydroxyphenyl]2H-benzotriazole with polyethylene glycol 300; [Rxe2x80x94CH2CH2xe2x80x94COOxe2x80x94CH2CH2xe2x80x94]2 where R=3xe2x80x2-tert-butyl-4xe2x80x2-hydroxy-5xe2x80x2-2H-benzotriazol-2-ylphenyl, 2-[2xe2x80x2-hydroxy-3xe2x80x2-(xcex1,xcex1-dimethylbenzyl)-5xe2x80x2-(1,1,3,3-tetramethylbutyl)-phenyl]benzotriazole; 2-[2xe2x80x2-hydroxy-3xe2x80x2-(1,1,3,3-tetramethylbutyl)-5xe2x80x2-(xcex1,xcex1-dimethylbenzy)-phenyl]benzotriazole.
2.2.2-Hydroxybenzophenones, for example the 4-hydroxy, 4-methoxy, 4-octyloxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2xe2x80x2,4xe2x80x2-trihydroxy and 2xe2x80x2-hydroxy-4,4xe2x80x2-dimethoxy derivatives.
2.3. Esters of Substituted and Unsubstituted Benzoic Acids, as for example 4-tertbutyl-phenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoyl resorcinol, bis(4-tert-butylbenzoyl)resorcinol, benzoyl resorcinol, 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, 2-methyl-4,6-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate.
2.4. Acrylates, for example ethyl xcex1-cyano-xcex2,xcex2-diphenylacrylate, isooctyl xcex1-cyano-xcex2,xcex2diphenylacrylate, methyl xcex1-carbomethoxycinnamate, methyl xcex1-cyano-xcex2-methyl-p-methoxy-cinnamate, butyl xcex1-cyano-xcex2methyl-p-methoxy-cinnamate, methyl xcex1-carbomethoxy-p-methoxycinnamate and N-(xcex2-carbomethoxy-xcex2-cyanovinyl)-2-methylindoline.
2.5. Nickel Compounds, for example nickel complexes of 2,2xe2x80x2-thio-bis-[4-(1,3,3-tetramethylbutyl)phenol], such as the 1:1 or 1:2 complex, with or without additional ligands such as n-butylamine, triethanolarmine or N-cyclohexyldiethanolamine, nickel dibutyldithiocarbamate, nickel salts of the monoalkyl esters, e.g, the methyl or ethyl ester, of 4-hydroxy-3,5-di-tert-butylbenzylphosphonic acid, nickel complexes of ketoximes, e.g, of 2-hydroxy-4-methylphenyl undecylketoxime, nickel complexes of 1phenyl-4-lauroyl-5-hydroxypyrazole, with or without additional ligands.
2.6. Sterically Hindered Amines, for example bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate. bis(2,2,6,6-tetramethyl-4-piperidyl)succinate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) n-butyl3,5-di-tert-butyl-4-hydroxybenzylmalonate, the condensate of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, linear or cyclic condensate of N,Nxe2x80x2-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine, tris(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate, tetrakis-(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butane-tetracarboxylate, 1,1xe2x80x2-(1,2-ethanediyl)-bis-(3,3,5,5-tetramethylpiperazinone), 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, bis(1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate, 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decan-2,4-dione, bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)sebacate, bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)succinate, linear or cyclic condensates of N,Nxe2x80x2-bis-(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine, the condensate of 2-chloro-4,6-bis(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazine and 1,2-bis(3-aminopropylamino)ethane, the condensate of 2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine and 1,2-bis-(3-aminopropylamino)ethane, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione, 3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidin-2,5-dione, 3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)pyrrolidine-2,5-dione, a mixture of 4-hexadecyloxy- and 4-stearyloxy-2,2,6,6-tetramethylpiperidine, a condensation product of N,Nxe2x80x2-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-cyclohexylamino-2,6-dichloro-1,3,5-triazine, a condensation product of 1,2-bis(3-aminopropylamino)ethane and 2,4,6-trichloro-1,3,5-triazine as well as 4-butylamino-2,2,6,6-tetramethylpiperidine (CAS Reg. No. [136504-96-6]); N-(2,2,6,6-tetramethyl-4-piperidyl)-n-dodecylsuccinimid, N-(1,2,2,6,6-pentamethyl-4-piperidyl)-n-dodecylsuccinimid, 2-undecyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxo-spiro[4,5]decane, a reaction product of 7,7,9,9-tetramethyl-2-cycloundecyl-1-oxa-3,8-diaza-4-oxospiro[4,5]decane and epichlorohydrin, 1,1-bis(1,2,2,6,6-pentamethpiperidyfoxycarbonyl)-2-(4-methoxyphenyl)ethene, N,Nxe2x80x2-bis-formyl-N,Nxe2x80x2-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine, diester of 4-methoxy-methylene-malonic acid with 1,2,2,6,6-pentamethyl-4-hydroxypiperidine, poly[methylpropyl-3-oxy-4-(2,2,6,6-tetramethyl-4-piperidyl)]siloxane, reaction product of maleic acid anhydride-xcex1-olefin-copolymer with 2,2,6,6-tetramethyl-4-aminopiperidine or 1,2,2,6,6-pentamethyl-4-aminopiperidine.
2.7. Oxamides, for example 4,4xe2x80x2-dioctyloxyoxanilide, 2,2-diethoxyoxanilide, 2,2xe2x80x2-dioctyloxy-5,5xe2x80x2-di-tert-butoxanilide, 2,2xe2x80x2-didodecyloxy-5,5xe2x80x2-di-tert-butoxanilide, 2-ethoxy-2xe2x80x2-ethyloxanilide, N,Nxe2x80x2-bis(3-dimethylaminopropyl)oxamide, 2-ethoxy-5-tert-butyl-2xe2x80x2-ethoxanilide and its mixture with 2-ethoxy-2xe2x80x2-ethyl-5,4xe2x80x2-di-tert-butoxanilide, mixtures of o- and p-methoxy-disubstituted oxanilides and mixtures of o- and p-ethoxy-disubstituted oxanilides.
2.8.2-(2-Hydroxyphenyl)-1,3,5-triazines, for example 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis-(4-methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-tridecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-butyloxy-propoxy)phenyl]-4,6-bis(2,4-dimethyl)-3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-octyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine, 2-[4-(dodecyloxy/tridecyloxy-2-hydroxypropoxy)-2-hydroxy-phenyl]-4,6-bis(2,4-di-methylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxy-propoxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-hexyloxy)phenyl-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2,4,6-tris[2-hydroxy-4-(3-butoxy-2-hydroxy-propoxy)phenyl]-1,3,5-triazine, 2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-6-phenyl-1,3,5-triazine, 2-{2-hydroxy-4-[3-(2-ethylhexyl-1-oxy)-2-hydroxypropyloxy]phenyl}-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.
3. Phosphites and Phosphonites, for example triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl)phosphite, trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythritol diphosphite, tris(2,4di-tert-butylphenyl)phosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)-pentaerythritol diphosphite, diisodecyloxypentaerythritol diphosphite, bis(2,4-di-tert-butyl-6-methylphenyl)pentaerythritol diphosphite, bis(2,4,6-tris(tert-butylphenyl)pentaerythritol diphosphite, tristearyl sorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl) 4,4xe2x80x2-biphenylene diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenz[d,g]-1,3,2-dioxaphosphocin, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenz[d,g]-1,3,2-dioxaphosphocin, bis(2,4-di-tert-butyl-6-methylphenyl) methyl phosphite, bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite, 2,2xe2x80x2,2xe2x80x3-nitrilo[triethyltris(3,3xe2x80x2,5,5xe2x80x2-tetra-tert-butyl-1,1xe2x80x2-biphenyl-2,2xe2x80x2-diyl)phosphite], 2-ethylhexyl(3,3xe2x80x2,5,5xe2x80x2-tetra-tertutyl-1,1xe2x80x2-biphenyl-2,2xe2x80x2-diyl)phosphite.
Especially Preferred are the Following Phosphites:
Tris(2,4-di-tert-butylphenyl) phosphite (Irgafos(copyright)168, Ciba-Geigy), tris(nonylphenyl) phosphite, 
Very particular preference is given to tris(2,4-di-tert-butylphenyl) phosphite [Irgafos(copyright)168, Ciba-Geigy], bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite [Irgafos(copyright)38, Ciba-Geigy, formula (G)] and 2,2xe2x80x2,2xe2x80x3-nitrilo[triethyl tris(3,3xe2x80x2,5,5xe2x80x2-tetra-tert-butyl-1,1 xe2x80x2-biphenyl-2,2xe2x80x2-diyl) phosphite [Irgafos(copyright)12, Ciba-Geigy, formula (B)].
4. Polyamide Stabilisers, for example, copper salts in combination with jodides anchor phosphorus compounds and salts of divalent manganese.
5. Fillers and Reinforcing Agents, for example, calcium carbonate, silicates, glass fibers, glass bulbs, asbestos, talc, kaolin, mica, barium sulfate, metal oxides and hydroxides, carbon black, graphite, wood flour and flours or fibers of other natural products, synthetic fibers.
6. Other Additives, for example, plasticisers, lubricants, emulsifiers, pigments, rheology additives, catalysts, flow-control agents, optical brighteners, flameproofing agents, antistatic agents and blowing agents.
The additional additives and/or stabilizers are added to the polycondensate in concentrations, for example, of from 0.01 to 10%, based on the overall weight of the polycondensate.
Among such additions, preference is given to light stabilizers from classes 2.1, 2.6 and 2.7, for example light stabilizers of the type Chimassorb(copyright)944, Chimassorb(copyright)19, Tinuvin(copyright)34, Tinuvine(copyright)312, Tinuvin(copyright)8622 or Tinuvin(copyright)770. Preference is also given to aromatic phosphites or phosphonites.
Where the polycondensate is a recyclate, it can also be employed mixed with virgin material or together with virgin material, for example in a coextrusion process.
The invention additionally provides for the use of an aromatic dicyanate for increasing the molecular weight and/or viscosity of virgin polycondensate or polycondensate recyclate.
The invention also provides for the use of a mixture comprising an aromatic dicyanate and, in addition, at least one polyfunctional compound selected from the class of the sterically hindered hydroxyphenyl-alkyl-phosphonic esters and monoesters, diphosphonites and secondary aromatic amines for increasing the molecular weight and/or viscosity of virgin polycondensate or polycondensate recyclate.
The present invention also provides for the use of a mixture comprising (i) an aromatic dicyanate, (ii) at least one polyfunctional compound selected from the class of sterically hindered hydroxyphenyl-alkyl-phosphonic esters and monoesters, diphosphonites and secondary aromatic amines, and (iii) a difunctional epoxide for increasing the molecular weight and/or viscosity of virgin polycondensate or polycondensate recyclate.
The preferences regarding the use correspond to those for the process.
The invention provides, furthermore, a composition comprising (a) a virgin polycondensate or polycondensate recyclate or a mixture thereof, and (b) an aromatic dicyanate.
The Invention additionally provides a composition comprising (a) a virgin polycondensate or polycondensate recyclate or a mixture thereof, (b) an aromatic dicyanate, and (c) at least one polyfunctional compound selected from the class of the sterically hindered hydroxyphenyl-alkyl-phosphonic esters and monoesters, diphosphonites and secondary aromatic amines.
The present invention additionally provides a composition comprising (a) a virgin polycondensate or polycondensate recyclate or a mixture thereof, (b) an aromatic dicyanate, (c) at least one polyfunctional compound selected from the class of the statically hindered hydroxyphenyl-alkyl-phosphonic esters and monoesters, diphosphonites and secondary aromatic amines, and (d) a difunctional epoxide.
The preferences regarding the compositions correspond to those for the process.
The invention further provides, in addition, polycondensates obtainable by the novel process.